According to Wikipedia, a glog is a graphical blog or an online rich media poster. It's basically a blog made with images & video with the ability to add text & links.Glogster Edu is a place for anyone to create their own glog and it even allows teachers to register a virtual class. Also allows students to look at and comment on each other's glogs. Some ideas for classroom use: end of unit reflection, posters to illustrate topic themes, 'Wanted' posters about individuals critical to a unit of study. Glogs allow students creative expression of knowledge and skills in the classroom and beyond. It empowers students with the technology to create their own online multimedia posters - with text, photos, videos, graphics, sounds, drawings, data attachments and more, to creatively demonstrate their knowledge.

http://edu.glogster.com/

A blog is a website in which items are posted on a regular basis and displayed in reverse chronological order. The term blog is a shortened form of weblog or web log. Authoring a blog, maintaining a blog or adding an article to an existing blog is called “blogging”. Individual articles on a blog are called “blog posts,” “posts” or “entries”. A person who posts these entries is called a “blogger”. A blog comprises text, hypertext, images, and links (to other web pages and to video, audio and other files). Blogs use a conversational style of documentation. Often blogs focus on a particular “area of interest”, such as Washington, D.C.’s political goings-on. Some blogs discuss personal experiences - there are many in use - some of the popular ones are:

Blogger
Wordpress
EduBlogs

1. Classroom Management
One of the obvious uses of using a blog is classroom management: handouts, homework assignments, videos, and presentations among other things can be posted to the blog. The blog can also act as a question and answer board through the use of comments.

2. Connect with the Parents
Sharing photos or videos in addition to posting announcements is an excellent way to connect the wonderful things going on in your classroom

3. Collaboration

*When students write to a blog, they are writing to an authentic audience. The writing is not just between student and teacher and sometimes the parents. The writing is available for all to see providing motivation to excel.
*Blogs allow a space for collaboration between students and teachers.
*Extends learning to the home (if students go home and chat or go to Facebook, why not have them on your blog or wiki instead?).
*Provides the opportunity to teach students about responsible writing.

Kathy Shrocks top educational blogs http://kathyschrock.net/edtechblogs.htm
educational blogs to investigate http://mrssmoke.onsugar.com/Educational-Blogs-You-Should-Investigating-2787268
Technology4thinking super teacher blog
Integrating technology in the classroom
iPads deployment blog from a school in Scotland